Equisetum variegatum is a rhizomatous, evergreen member of the horsetail family (Equisetaceae) found in moist open soil, meadows, and frequently gravel bars. Equisetum variegatum grows from a smooth rhizome. The stems are often tufted, may be bent or decumbent, but are usually ascending. The stems grow up 40 cm tall in Denali and are up to 3 mm in diameter. The sterile and fertile stems are the same. They are mostly unbranched, though there may be a few branches at the base. The central cavity of the stems is one-quarter the stem diameter. The cones are apiculate and small (up to 7 mm long). E. variegatum is most similar to E. scirpoides which is also evergreen and unbranched but E. scirpoides does not have a central cavity in its stems and is wiry and tufted.
The cones of Equisetum variegatum mature and shed spores in late summer or persist unopened until the following spring.
Equisetum species reproduce sexually and asexually. Sexual reproduction is limited by ecological conditions. hygroscopic spores are produced, but they are short lived and germinate depending on humidity. Once germinated, the gametophyte produced by spores requires a recently exposed substrate to become established. Asexual reproduction is by rhizomatous growth which can be rapid in favorable moist and disturbed habitats. Reproduction also occurs by fragmentation of rhizomes and stems. Clones may spread rapidly, and since usually they are sterile, may establish characters indicating taxonomic differentiation.
Refer to Equisetum arvense for the known uses of horsetails and scouring rushes in general. Moerman (1998) reports that E. variegatum was used by the Yuki Indians as an eye medicine for sore eyes, and as sandpaper for finishing arrows by the Mendocino Indians.
Equisetum variegatum is a widespread circumpolar species. Outside of North America this species occurs in Europe, northern Asia east to Kamchatka. In North America E. variegatum occurs from Greenland to Alaska, south to Oregon, Utah, Michigan, New York, and New England. E. variegatum subsp. alaskanum occurs in southeast Alaska, southwestern Yukon Territory, along the British Columbia coast to Vancouver Island. E. variegatum occurs on both sides of the Alaska Range in Denali.
Throughout its North American range, Equisetum variegatum occurs at altitudes of 0-3500. It occurs at 116-1752 m in Denali, at an average of 644 m, and with the majority of occurrences at 800-1100 m. It has the greatest elevation range of all species in the genus in the park. Most occurrences were on flat terrain (slopes less than five degrees), 16% were on south-facing slopes and 11% were on north-facing slopes. Populations on south-facing slopes occurs on slopes as steep as 38 degrees but most occurrences were on mild to moderate slopes (between 8-22 degrees). Most populations on north-facing slopes were on mild slopes (between 7-16 degrees).